The present invention relates to a production method of biodegradable plastic made from lactic acid as a raw material and apparatus for use in the production thereof.
The production method of polylactic acid, a main component of biodegradable plastic, using lactic acid as the raw material is known, and as illustrated in FIG. 1, the conventional method generally consisted of the synthetic process in which lactic acid is converted to polylactic acid via lactide by means of condensation polymerization of lactic acid by dehydration under high temperature and pressure.
Biodegradable plastic is provided with functions and performance as plastic for ordinary use, and is characterized in that the plastic is readily decomposed and rendered harmless in the natural environment when thrown away after use and does not pollute the natural environment. Therefore, the plastic is expected to be used in every field in the near future and is an extremely useful material.
However, the plastic has been used only for compost bags, multi-film used in agriculture and the like since the production cost for the above conventional production method has been high and the plastic had disadvantage such that enough strength and performance could not be attained compared to general-purpose plastic, while it is beginning to be utilized in the field of medicine such as surgical suture owing to its excellent biocompatibility.